Answer:

Step-by-step explanation:
From the Venn diagram, n(AUB)=31
The given probabilities in the option are calculated below:

The only correct option is the probability of B which is 
The length of side b is 7.61 m.
Here's how the length was calculated:
Let:
length of side a = 12 centimeters
B = 36 degrees
C = 75 degrees
In order to solve an AAS triangle, use the three angles, add to 180 degrees to find the other angle, then, use The Law of Sines to find each of the other two sides.
A = 180 - (36 + 75) = 69 degrees
by using the law of sines:
a / sin A = b / sin B = c/ sin C
we will substitute the given values:
12 / sin (69) = b / sin (36)
b = unknown
12 / 0.93 = b / 0.59
12.9 = b / 0.59
b = 12.9 * 0.59
b =7.61 cm (length of side b)
The price of the discount is $25 x 0.15 = $3.75
The price of the book with discount is $25 - $3.75 = $21.25
I think B is the closest answer